Design of a Medical Record Information System for the Thoracic and Cardiovascular Surgery Unit at Melinda Hospital

Medical documentation in the Thoracic and Cardiovascular Surgery (TCVS) Unit is highly complex, involving real-time hemodynamic monitoring, Heart-Lung Machine (HLM) parameters, cardiopulmonary bypass (CPB) duration, fluid balance, and surgical-site marking on cardiac anatomy diagrams. However, the existing hospital information system (SIMRS Teramedic) at Melinda Hospital still separates the preoperative, intraoperative, and postoperative forms, and the intraoperative form in particular is still recorded together with physical files, leading to duplicate records. This study aims to design a web-based Electronic Medical Record (EMR) information system for the TCVS Unit, integrated with the Teramedic database, using the Waterfall method. The application was developed using native PHP, MySQL, Chart.js, the HTML5 Canvas API for interactive anatomical plotting, and html2pdf. The system includes atomic (ACID) transactions, role-based access control (RBAC), CSRF protection, request rate limiting, a password policy, prepared statements, and audit logs. Functional testing used black-box testing, including transaction-failure testing. The results showed 100% reliability (all scenarios valid) and an average System Usability Scale (SUS) score of 78.5 (Grade A). The system is functionally feasible, secure, and highly usable for improving the efficiency and accuracy of medical documentation. Future research should evaluate full Teramedic API integration in a production environment and quantify its impact on data-entry time.